JPS607212B2 - colorimeter - Google Patents

Description

[Detailed description of the invention] The present invention relates to a colorimeter.

Colorimetric analysis is an important chemical analysis method in which a colorimeter is used to quantify a substance by comparing the color tone or color intensity of a solution with that of a standard solution. It is often used for measurements, etc.

However, conventional colorimeter has the disadvantage that it cannot perform accurate colorimetric analysis because of its poor accuracy.This is because conventional colorimeter is installed in a dark room etc. Colorimetric analysis is performed with external light blocked, but it is not possible to completely block out external light, and the harmful light (suicide light) is irradiated onto the sample material, causing the original color to be lost. This is due to the fact that colorimetric analysis is performed without distinction from continuous irradiation light from a light source in a colorimeter.

Therefore, a mechanically driven disk with slits is provided between the light source and the sample material in the colorimeter to obtain intermittent irradiation light, and this intermittent irradiation light prevents changes in the colorimetric analysis due to stray light. Such colorimeter has been put into practical use.

However, although this type of colorimeter can perform accurate colorimetric analysis, it has the drawbacks of being a large-scale device, lacking in versatility, and being expensive.

Therefore, an object of the present invention is to provide a novel colorimeter that eliminates the above-mentioned conventional drawbacks, is compact, has excellent versatility, and is capable of performing highly accurate colorimetric analysis with no influence of stray light. Our goal is to provide the following.

In order to achieve this purpose, in the present invention, a sample material is irradiated with a light source that is ignited intermittently by a non-DC power source that generates alternating current or pulsed current, and the sample material is obtained by removing the direct current component from the output. This is a colorimeter characterized in that it is configured to perform colorimetric analysis.

Hereinafter, a colorimeter which is an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a colorimeter according to the present invention.

In the figure, 1 is a light source, and a small tungsten lamp is used. 2 is a non-DC power source that generates alternating current or pulsed current, and is used to ignite the small tungsten lamp 1 intermittently.

3 is a reference sample (standard solution), 4 is a colorimetric analysis substance (test sample), 5 to 6 are photodetection cells, and 5 detects the transmitted light from the reference sample 3 and converts it into an electrical signal. and
6 detects the transmitted light from the test sample 4 and converts it into an electrical signal.

7 to 8 are DC band cancellation filters.

In the amplifiers 9 to 1, 9 is an amplifier for amplifying the differential AC output, and 10' is an amplifier for amplifying the reference input of the phase detector 11. 12 is an indicator which is an output display meter.

The operation of the colorimeter according to the present invention will be explained with reference to the drawings.

When a small tungsten lamp 1 is ignited by a non-DC power source 2 that generates an alternating current or pulsed current (Fig. 2), the filament of this small tungsten lamp 1 has an extremely small heat capacity, so the alternating current or pulsed frequency emits intermittent light or light of varying intensity that is modulated by

This intermittent light enters the reference sample 3 and the test sample 4, and the transmitted light enters the respective photodetection cells 5 to 6 and is converted into an electrical signal. FIG. 3 shows the output of the photodetection cell 5 on the reference sample 3 side, and FIG. 4 shows the output of the photodetection cell 6 on the test sample 4 side. Each DC component in Figures 3 and 4 is generated due to stray light, and strictly speaking, the stray light incident on the reference sample 3 and the stray light incident on the test sample 4 have different amounts of light. , each DC component caused by them also shows different values. In this case, if the concentration of the test sample 4 is zero, the output of the photodetection cell 6 is adjusted to be zero. The output difference between the photodetection cells 5 and 6 on the reference sample 3 side and the test sample 4 side is determined by the DC band cancellation filter 7.
As a result, the DC component (this is a harmful output that intervenes due to stray light) of the output difference is removed, and only the AC or pulse current component (Figure 5) is amplified by the amplifier 9 (Figure 6). ), detected by the phase detector 11 (
(FIG. 7), indicated by the indicator 12.

On the other hand, the reference input of the phase detector 11 is obtained by amplifying the output of the detection cell 5 on the reference sample 3 side by an amplifier 10 via a DC band elimination filter 8.

By providing this circuit network, it is possible to eliminate the need for phase adjustment by replacing the small tungsten lamp 1, which is the light source, with another small tungsten lamp due to deterioration over time. As described above, the colorimeter according to the present invention uses a non-DC power source that generates alternating current or pulsed current to intermittently ignite a small tungsten lamp, and uses the discontinuous light emitted from the lamp to detect the reference sample 3 and the test object. Sample 4 is irradiated and colorimetric analysis is performed. Of the outputs from the photodetection cells 5 to 6, the direct current component generated by stray light is removed, and colorimetric analysis is performed using only the outputs from the above-mentioned discontinuous light. therefore,
The colorimeter according to the present invention has the following features. Since the incident light for performing the '1' colorimetric analysis is intermittent light, minute changes in absorbance can be measured with high sensitivity and accuracy without being affected by stray light, which is continuous light. [2] Intermittent light is obtained by operating a small tungsten lamp with a non-DC power source, resulting in a compact device that can be manufactured at low cost.

[3' As the non-DC power source, a power source that generates alternating current or pulse current can be used, and as the light source, a small tungsten lamp or the like with low power consumption can be used.

Therefore, colorimetric analysis can be performed using a commercial frequency AC power source for general household use or a battery-driven pulse current generating power source. Therefore, the colorimeter according to the present invention is a handy device and is not affected by stray light, and can be used outdoors or anywhere.
It has excellent versatility and can be expected to have a wide range of uses. In addition, in the colorimeter according to the present invention illustrated in FIG.
The DC component caused by stray light is removed by the DC band cancellation filters 7 to 8. By using an amplifier that also has the functions of the DC band cancellation filters 7 to 8,
When the DC component of the reference sample due to stray light and the DC component of the test sample are almost the same, their output difference cancels each other out, and only the non-DC component can be detected even without the DC band elimination filter 7). Even with an apparatus in which filters 7 and 8 of this type are omitted, the object of the present invention can be achieved.

In this case, by applying the secondary colorimeter as is and replacing its light source and power source with a small tungsten lamp and a non-DC power source to drive it, it is possible to prevent the accuracy of colorimetric analysis from decreasing due to stray light. be.

[Brief Description of the Drawings] Fig. 1 is a diagram showing a colorimeter which is an embodiment of the present invention, Fig. 2 is a diagram showing a colorimeter which is an embodiment of the present invention;
7 to 7 are diagrams for explaining the operation of the colorimeter according to the present invention. 1...Small tungsten lamp, 2...Non-DC power supply, 3...Reference sample, 4...Test sample, 5-6...Photodetection cell, 7-8...DC band cancellation filter, 9-10...Amplifier, 11...
・Detector, 12... Indicator. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Scope of Claims] 1. A method characterized in that the sample substance is irradiated with a light source that is ignited intermittently by a non-DC power source, and the output obtained by removing the DC component is used for colorimetric analysis of the sample substance. Color meter. 2. The colorimeter according to claim 1, wherein a tungsten lamp is used as the light source. 3. The colorimeter according to claim 1, wherein the non-DC power source is a power source that generates alternating current or pulsed current.